Weld-Neck Flanges | McMaster-Carr

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441 Products

How to Identify and Measure Fittings

Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.

Low-Pressure Steel Unthreaded Pipe Flanges

Bolt two flanges of the same size together with a gasket to create an access point in a pipe line.

Low-Pressure Steel Unthreaded
Pipe Flanges for Low Temperatures

Even in temperatures as low as -46°, these A350 LF2 steel flanges won’t become brittle, so they absorb impact better than other low-pressure steel flanges.

High-Pressure Steel Unthreaded Pipe Flanges

Forged for extra strength, these heavy duty unthreaded flanges can withstand high-pressure applications.

High-Pressure Steel Unthreaded SAE Pipe Flanges

Also known as Code 61 SAE hydraulic flanges.

Extreme-Pressure Steel Unthreaded Pipe Flanges

For excellent strength in extreme-pressure applications, choose these heavy duty Pressure Class 1500 flanges.

Low-Pressure Stainless Steel
Unthreaded Pipe Flanges

Bolt two same-size flanges together with a gasket to create an access point within a pipe line.

High-Pressure Stainless Steel
Unthreaded Pipe Flanges

Use these heavy duty forged flanges for high-pressure applications.

High-Pressure Stainless Steel
Unthreaded SAE Pipe Flanges

Also known as Code 61 SAE hydraulic flanges.

Aluminum Unthreaded Pipe Flanges

Use these unthreaded flanges in low-pressure applications. Also known as Pressure Class 125 flanges.

High-Purity Polypropylene Pipe
Flanges for Corrosive Chemicals

The inside of these flanges won’t leach contaminants into your line or accumulate particles—they’re polished to an ultra-smooth 12 Ra finish, which also makes them easy to clean. Made of polypropylene, they resist organic solvents, acids, and alkalis better than CPVC pipe flanges.

Ultra-High-Vacuum Flanges and Fittings for Stainless Steel Tubing

Ultra-High-Vacuum Flanges and
Fittings for Stainless Steel Tubing

Create access points in ultra-high-vacuum lines or chambers by bolting two same-size flanges together with a copper gasket between them. The flanges’ sharp edges dig into the copper gasket and form an extremely tight seal, which means they handle higher vacuum pressures than other high-vacuum fittings with rubber gaskets.

Flow-Control Flange Unions

Measure, throttle, and regulate the flow of liquids and gases in your line by adding an orifice plate to these unions.